WEYMOUTH—Dr. Gerald Maher’s Web site declares that no New England Patriots player wearing his patented mouth guard has ever suffered a concussion from a blow to the jaw.

So, what about Ted Johnson?

Johnson, the former thick-necked inside linebacker, retired from the NFL on the eve of the 2005 season, citing the cumulative effect of multiple concussions. He sprang back into the news on the eve of Super Bowl XLI this past February when he told the Boston Globe and the New York Times that the head injuries had rendered him incapable of living a normal life. He blamed Patriots coach Bill Belichick for forcing him to practice with a concussion in the 2002 preseason.

Johnson would seem to be the fly in Maher’s ointment, but the Patriots’ team dentist has an explanation—Johnson’s troubles might have been caused by blows to the helmet, not the jaw.

‘‘I don’t want to look like I’m using it as a cop-out: ‘His jaw’s in great shape; he had a helmet problem,’’’ Maher said. ‘‘It doesn’t sound (good). It almost sounds like I’m making the helmet a scapegoat.’’

Yet Maher stands by his version of events. He also doesn’t like the way Johnson pointed the finger at Belichick.

‘‘He’s a tremendous man, he’s a tremendous human being,’’ Maher said of the coach. ‘‘To denigrate his character the way Johnson has, I just think is wrong. (Johnson) never said anything to me about a concussion in 10 years.’’

Maher has been outfitting Patriots players with his mouth guards since the early 1980s and said that 40 current members of the team wear them. Johnson wore one.

"To not have a TMJ [temporomandibular joint] expert on the panel is extremely shortsighted," said Maher. "I don't understand why they don't. It's one of the pieces that we should be looking at. We should be looking at prevention."

Part of the NFL's concussion crackdown, which includes neurological baseline testing for all players, will be to enforce the use of chin straps. Maher said that's more likely to hurt than help, as it locks the jaw in a position where the end of the jawbone can strike the temporal lobe of the brain.

"That's the worst possible physiological position they can put it in," said Maher.

The Patriots have not had one concussion this season, yet the NFL sits and waits for a study, meanwhile players like Green, Coles, Hamilton, Thomas all remain in the dark.